1. Field of the Invention
The present invention relates to a supply modulator.
2. Description of the Related Art
A supply modulator is a device for modulating Direct Current (DC) power to supply Alternating Current (AC) power that changes in accordance with an input signal to a load. The supply modulator is primarily utilized in a mobile communication terminal for converting an input baseband signal to an output Radio Frequency (RF) signal at high efficiency using limited battery power. To meet performance requirements that are increasingly difficult to attain, such as a broadband trend of a process signal, a high Peak to Average Power Ratio (PAPR), etc., the supply modulator utilized in the mobile communication terminal is evolving so as to be implemented by a more efficient structure. In the related art, a supply modulator that independently applies a linear regulator or a Switching Mode Power Supplier (SMPS) technology primarily utilized as a DC-DC converter in a power Integrated Circuit (IC) field has been realized. However, to address a technical limitation, a supply modulator of a hybrid structure including both the linear regulator and the SMPS has been suggested.
In a case of a supply modulator including only one of the linear regulator and the SMPS, optimization to tune for a particular system situation is performed. However, despite optimization, similar protection devices in aspects of a structure and concept may be applied to all cases. However, in a case of a hybrid supply modulator where the linear regulator and the SMPS are coupled as core elements, an abnormal situation in which a protection action should be provided will appear in a different form at a point different from a case of a supply modulator including only one of the linear regulator and the SMPS.
Therefore, there is a need for an alternative for recognizing an abnormal situation and performing a protection action in a hybrid supply modulator.